easy p-cheesy

My idle had been kind of funny. felt like some clunking or something. its hard to explain.I posted about it and someone suggested dumping fuel system cleaner in the next tank of gas. well, I did. and I noticed immediate results. which made me think it might not be the cleaner. how long does it take for it to work? I had also had 89 in it for some reason. and this time I put in 87. It seems to be idling very very smoothly now and I'm feeling noticable power gain. looks like I had some messed up stuff. If anyone hasn't done this for a while, I'd say definately do it.